Benthic bacterial biomass and production in the Hudson River estuary.

Bacterial biomass, production, and turnover were determined for two freshwater marsh sites and a site in the main river channel along the tidally influenced Hudson River. The incorporation of [methyl-(3)H]thymidine into DNA was used to estimate the growth rate of surface and anaerobic bacteria. Bacterial production at marsh sites was similar to, and in some cases considerably higher than, production estimates reported for other aquatic wetland and marine sediment habitats. Production averaged 1.8-2.8 mg C·m(-2)·hour(-1) in marsh sediments. Anaerobic bacteria in marsh sediment incorporated significant amounts of [methyl-(3)H]thymidine into DNA. Despite differences in dominant vegetation and tidal regime, bacterial biomass was similar (1×10(3)±0.08 mg C·m(-2)) inTrapa, Typha, andNuphar aquatic macrophyte communities. Bacterial abundance and productivity were lower in sandy sediments associated withScirpus communities along the Hudson River (0.2×10(3)±0.05 mg C·m(-2) and 0.3±0.23 mg C·m(-2)·hour(-1), respectively).